Implications of Single-Arm Blood Pressure Measurement during Aerobic Exercise

Blood pressure (BP) is commonly measured to diagnose hypertension and inform safe exercise participation. In clinical settings, BP is generally measured in one arm, disregarding the opposite arm and potential inter-arm differences (IAD) in BP. A commonly cited best practice suggests measuring BP in both arms at rest, and then monitoring the higher measured arm moving forward (e.g., exercising BP). Aerobic exercise (AE), often utilized to reveal underlying cardiovascular risk undetectable at rest or improve health, is known to acutely change BP. Previous data from our lab also suggests that AE alters IAD, and that the higher arm BP may shift during an AE session. In this retrospective analysis, we examined data from a series of four AE studies in our lab that documented bilateral BP responses during 1) progressive, low-intensity AE, 2) steady-state, low-intensity AE, 3) steady-state moderate-intensity AE, and 4) progressive, vigorous-intensity AE. Briefly, the higher arm during each participant's resting bilateral BP measurements was determined, and participants with no IAD were excluded from analysis. Subsequently, the instance of missed higher systolic or diastolic BP measurements in the lower arm were determined during the participant's AE and recovery stages. Interestingly, there were many instances of higher BP measures in the lower arm. For example, during progressive, low-intensity exercise, participants with a higher right arm BP at rest (n=58) had a higher BP in the left arm 14-19% of the time during AE. Surprisingly, participants with a higher left arm BP at rest (n=17) had a higher right arm BP 35-53% of the time during AE. Similar instances will be reported from multiple studies. Based on our findings, true bilateral BP readings may have clinical relevance in the accurate management of AE testing and intervention.